71% of carbon found dissolved in oceans. Oceans acts as the largest carbon sink/reservoir and regulates amount of CO2 in atmosphere. Annual fixation of carbon through Photosynthesis −4×1013Kg− according to an estimate, out of the total incident light received by earth, only 50% is suitable for Photosynthesis - PAR (Photosynthetically active radiation) Productivity of oceans is only 55 billion tons due to low nitrogen, organic nutrients.